scholarly journals SCIDOT-41. NANOTHERAPEUTIC TARGETING OF TUMOR ENDOTHELIUM FOR ENHANCING DRUG DELIVERY PAST THE BLOOD-BRAIN BARRIER

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi280-vi280
Author(s):  
Hiroto Kiguchi ◽  
Mandana Manzari ◽  
Jake Vaynshteyn ◽  
Jeffrey Gerwin ◽  
Daniel Tylawsky ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Low Dose ◽  
Tumor Vasculature ◽  
Adult Brain ◽  
Brain Barrier ◽  
Dependent Manner ◽  
Shh Pathway ◽  
Blood Brain

Abstract OBJECTIVE The Sonic Hedgehog (SHH) medulloblastoma subgroup accounts for ~25% of all cases and has an intermediate prognosis. Current conventional therapies result in devastating morbidities including intellectual disability and secondary malignancies. Although molecularly targeted agents that inhibit the SHH pathway have demonstrated clinical efficacy, recent studies have shown on-target secondary toxicities on bone development suggesting new therapeutic approaches are needed. METHODS We investigated the efficacy of the SHH pathway inhibitor, Vismodegib packaged in a fucoidan-based nanoparticle (Fi-Vis) that targets P-selectin, a protein overexpressed on vascular endothelial cells and induced by low-dose ionizing radiation (XRT) in a time- and dose-dependent manner. This P-selectin targeting nanoparticle drug delivery system shows selectivity toward tumor vasculature and not normal brain vasculature in a genetic SHH medulloblastoma mouse model as assessed by ex vivo infrared imaging and two-photon intravital imaging. RESULTS Quantitative RT-PCR analysis of SHH medulloblastoma tissue following single dose XRT and Fi-Vis treatment (10mg/kg) showed a synergistic inhibition of Gli1 expression (>90% target inhibition). Furthermore, we demonstrate that very low dose XRT (0.25Gy) can induce P-selectin expression specifically within MB tumor vasculature and synergize with low dose Fi-Vis (10mg/kg) to significantly enhance mouse survival (p<0.01) when compared to radiation or Fi-Vis alone. Furthermore, assessment of bone toxicity using micro-CT and histological analysis following Fi-Vis administration in postnatal (P10) mice shows no bone toxicity when compared to free Vismodegib. Finally, in vitro studies using mouse brain endothelial cells suggest at least in part a caveolin-1 mediated transcytosis mechanism of crossing the endothelial blood-brain barrier. CONCLUSIONS These data suggest applicability of combined XRT and tumor vasculature-targeted nanotherapeutic dose de-escalation strategies for SHH medulloblastoma with implications for other pediatric and adult brain tumors.

scholarly journals DDEL-15. NANOTHERAPEUTIC TARGETING OF TUMOR ENDOTHELIUM FOR ENHANCING DRUG DELIVERY PAST THE BLOOD-BRAIN BARRIER

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii286-iii286
Author(s):  
Hiro Kiguchi ◽  
Daniel Tylawsky ◽  
Jake Vaynshteyn ◽  
Jeffrey Gerwin ◽  
Mandana Manzari ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Low Dose ◽  
Brain Barrier ◽  
Pcr Analysis ◽  
Normal Brain ◽  
Dependent Manner ◽  
Shh Pathway ◽  
Blood Brain ◽  
Tumor Endothelium

Abstract OBJECTIVE The Sonic Hedgehog (SHH) medulloblastoma subgroup accounts for ~25% of all cases and has an intermediate prognosis. Current therapies result in devastating morbidities including intellectual disability and secondary malignancies. Although molecularly targeted agents against the SHH pathway have demonstrated efficacy, on-target bone toxicities suggest new therapeutic approaches are needed. METHODS We investigated the SHH pathway inhibitor, vismodegib, packaged in a fucoidan-based nanoparticle (Fi-Vis) that targets P-selectin expressed on endothelial cells and induced by low-dose ionizing radiation (XRT) in a time- and dose-dependent manner. This P-selectin targeting nanoparticle shows selectivity toward tumor and not normal brain vasculature in a GEM SHH medulloblastoma model as assessed by ex vivo infrared imaging and molecular studies. RESULTS Quantitative RT-PCR analysis of SHH medulloblastoma following single dose XRT and Fi-Vis treatment (10mg/kg) showed synergistic reduction of Gli1 expression (&gt;90% target inhibition). We demonstrate that low-dose XRT (0.25Gy) can induce P-selectin expression specifically on medulloblastoma tumor endothelium and synergize with low-dose Fi-Vis (10mg/kg) to significantly enhance mouse survival (p&lt;0.01) compared to radiation or Fi-Vis alone. Assessment of bone toxicity using micro-CT and histological analysis following Fi-Vis administration in postnatal (P10) mice shows no bone toxicity when compared to free vismodegib. Finally, in vitro studies using bEnd.3 brain endothelial cells and in vivo studies using Cav1 knockout mice suggest a caveolin-1 mediated transcytosis mechanism for nanoparticle entry across the blood-brain barrier. CONCLUSIONS These data suggest applicability of combined XRT and tumor vasculature-targeted nanotherapeutic dose de-escalation strategies for SHH medulloblastoma with implications for other pediatric brain tumors.

Abstract 218: Pericytic Laminin Regulates Blood-Brain Barrier Integrity in an Age-Dependent Manner

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Yao Yao ◽  
Jyoti Gautam ◽  
Xuanming Zhang
Keyword(s):  
Endothelial Cells ◽  
Basement Membrane ◽  
Blood Brain Barrier ◽  
Vessel Density ◽  
Brain Barrier ◽  
Dependent Manner ◽  
Vascular Integrity ◽  
Blood Brain ◽  
Age Dependent

Introduction: Laminin, a major component of the basement membrane, plays an important role in blood brain barrier (BBB) regulation. At the neurovascular unit, astrocytes, brain endothelial cells, and pericytes synthesize and deposit different laminin isoforms into the basement membrane. Previous studies from our laboratory showed that loss of astrocytic laminin induces age-dependent and region-specific BBB breakdown and intracerebral hemorrhage, suggesting a critical role of astrocytic laminin in vascular integrity maintenance. Laminin α4 (predominantly generated by endothelial cells) has been shown to regulate vascular integrity at embryonic/neonatal stage. The role of pericytic laminin in vascular integrity, however, remains elusive. Methods: We investigated the function of pericyte-derived laminin in vascular integrity using laminin conditional knockout mice. Specifically, laminin floxed mice were crossed with PDGFRβ-Cre line to generate mutants (PKO) with laminin deficiency in PDGFRβ + cells, which include both pericytes and vascular smooth muscle cells (vSMCs). To distinguish the contribution of pericyte- and vSMC-derived laminin, we also generated a vSMC-specific condition knockout line (TKO) by crossing the laminin floxed mice with Transgelin-Cre mice. In this study, mice of both genders on a C57Bl6 background were used. At least 5-6 animals were used in biochemical and histological analyses in this study. Results: Pericyte-derived laminin was abrogated in all PKO mice. However, only old but not young PKO mice showed signs of BBB breakdown and reduced vessel density, suggesting age-dependent changes. Consistent with these data, further mechanistic studies revealed reduced tight junction proteins, diminished AQP4 expression, and deceased pericyte coverage in old but not young PKO mice. In addition, neither BBB disruption nor decreased vessel density was observed in TKO mice, suggesting that these vascular defects are due to loss of pericyte- rather than vSMC-derived laminin. Conclusions: These results strongly suggest that pericyte-derived laminin active regulates BBB integrity and vessel density in an age-dependent manner. I would like this abstract to be considered for the Stroke Basic Science Award.

scholarly journals Plasmodium falciparum erythrocyte membrane protein 1 variants induce cell swelling and disrupt the blood–brain barrier in cerebral malaria

2021 ◽  
Vol 218 (3) ◽  
Author(s):  
Yvonne Adams ◽  
Rebecca W. Olsen ◽  
Anja Bengtsson ◽  
Nanna Dalgaard ◽  
Mykola Zdioruk ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Plasmodium Falciparum ◽  
Cerebral Malaria ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Cell Swelling ◽  
Dependent Manner ◽  
Brain Endothelial Cells ◽  
Blood Brain ◽  
The Brain

Cerebral malaria (CM) is caused by the binding of Plasmodium falciparum–infected erythrocytes (IEs) to the brain microvasculature, leading to inflammation, vessel occlusion, and cerebral swelling. We have previously linked dual intercellular adhesion molecule-1 (ICAM-1)– and endothelial protein C receptor (EPCR)–binding P. falciparum parasites to these symptoms, but the mechanism driving the pathogenesis has not been identified. Here, we used a 3D spheroid model of the blood–brain barrier (BBB) to determine unexpected new features of IEs expressing the dual-receptor binding PfEMP1 parasite proteins. Analysis of multiple parasite lines shows that IEs are taken up by brain endothelial cells in an ICAM-1–dependent manner, resulting in breakdown of the BBB and swelling of the endothelial cells. Via ex vivo analysis of postmortem tissue samples from CM patients, we confirmed the presence of parasites within brain endothelial cells. Importantly, this discovery points to parasite ingress into the brain endothelium as a contributing factor to the pathology of human CM.

Neurothelin: molecular characteristics and developmental regulation in the chick CNS

Development ◽  
1991 ◽  
Vol 113 (1) ◽  
pp. 129-140
Author(s):  
B. Schlosshauer
Keyword(s):  
Endothelial Cells ◽  
Membrane Proteins ◽  
Molecular Mass ◽  
Blood Brain Barrier ◽  
Adult Brain ◽  
Brain Barrier ◽  
Relative Molecular Mass ◽  
Brain Neurons ◽  
Blood Brain

Neurothelin has recently been identified as a cell surface protein specific for chick endothelial cells forming the blood-brain barrier. Neurons of the adult brain are essentially devoid of neurothelin. In contrast, neurons of the chick retina, which lack blood vessels and accessory astrocytes, express neurothelin. Here we demonstrate that during chick brain development initially neurothelin is expressed probably in all neuroblasts. With proceeding cytodifferentiation, such as vascularization and gliogenesis, brain neurons become neurothelin negative. Coincidentally the endothelial cells forming the blood-brain barrier start to synthesize neurothelin. In contrast to brain neurons, in retina neurons, neurothelin expression increases by one order of magnitude during the course of histogenesis. Coculturing of chick retinal cells with purified rat astrocytes in vitro results in reduction of neural neurothelin expression as quantified by ELISA. Conversely, disruption of the glia-neuron interactions by culturing brain neurons as individualized cells in vitro leads to a reexpression of neurothelin. This is consistent with the hypothesis that astrocytes inhibit neurothelin expression in neurons. Biochemical characterization classifies neurothelin as an integral membrane protein. Temperature-induced-detergent phase separation, phospholipase C digestion and sodium carbonate treatment were employed to distinguish between integral membrane proteins, lipid-anchored proteins and peripheral membrane proteins. Two-dimensional gel electrophoresis reveals an isoelectric point of about 6.4 for neurothelin. Polysaccharide analysis by glycosidase digestion and lectin binding indicates that neurothelin is highly glycosylated. The relative molecular mass of glycosylated neurothelin is 41 × 10(3), whereas the peptide backbone is only 25 × 10(3). The very strict spatiotemporal regulation of neurothelin expression in the central nervous system suggests that neurothelin fulfils possibly a crucial function such as transport of low relative molecular mass components that are essential for neuronal metabolism. The proposed biological activity of neurothelin might be specifically affected by some of its distinct biochemical features.

scholarly journals Methamphetamine Disrupts Blood–Brain Barrier Function by Induction of Oxidative Stress in Brain Endothelial Cells

2009 ◽  
Vol 29 (12) ◽  
pp. 1933-1945 ◽  
Author(s):  
Servio H Ramirez ◽  
Raghava Potula ◽  
Shongshan Fan ◽  
Tess Eidem ◽  
Anil Papugani ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Endothelial Injury ◽  
Brain Barrier ◽  
Dependent Manner ◽  
Monocyte Migration ◽  
Enhanced Production ◽  
Blood Brain ◽  
Neurotoxic Effects

Methamphetamine (METH), a potent stimulant with strong euphoric properties, has a high abuse liability and long-lasting neurotoxic effects. Recent studies in animal models have indicated that METH can induce impairment of the blood–brain barrier (BBB), thus suggesting that some of the neurotoxic effects resulting from METH abuse could be the outcome of barrier disruption. In this study, we provide evidence that METH alters BBB function through direct effects on endothelial cells and explore possible underlying mechanisms leading to endothelial injury. We report that METH increases BBB permeability in vivo, and exposure of primary human brain microvascular endothelial cells (BMVEC) to METH diminishes the tightness of BMVEC monolayers in a dose- and time-dependent manner by decreasing the expression of cell membrane-associated tight junction (TJ) proteins. These changes were accompanied by the enhanced production of reactive oxygen species, increased monocyte migration across METH-treated endothelial monolayers, and activation of myosin light chain kinase (MLCK) in BMVEC. Antioxidant treatment attenuated or completely reversed all tested aspects of METH-induced BBB dysfunction. Our data suggest that BBB injury is caused by METH-mediated oxidative stress, which activates MLCK and negatively affects the TJ complex. These observations provide a basis for antioxidant protection against brain endothelial injury caused by METH exposure.

scholarly journals SCIDOT-21. IMPROVING DRUG DELIVERY TO GLIOBLASTOMA BY TARGETING CANONICAL WNT/β-CATENIN SIGNALING IN THE BLOOD-BRAIN BARRIER

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi275-vi276 ◽  
Author(s):  
Amelie Vezina ◽  
Sadhana Jackson
Keyword(s):  
Drug Delivery ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Blood Brain Barrier ◽  
Cell Interaction ◽  
Brain Barrier ◽  
Beta Catenin ◽  
Brain Endothelial Cells ◽  
Junctional Proteins ◽  
Blood Brain

Abstract BACKGROUND Glioblastoma (GBM) patient survival and therapy response is greatly hindered by the presence of invasive glioma stem cells (GSC) and the blood-brain barrier (BBB) which limits effective drug delivery. WNT/beta-catenin signaling is important in the development and maintenance of the BBB by mediating transcription of growth factors, multidrug resistance proteins, and junctional proteins. In WNT-subtype medulloblastoma, activating mutations of beta-catenin lead to reciprocal secretion of WNT antagonists such as WIF1 and DKK1 into the tumor microenvironment. These WNT antagonists can act upon the surrounding endothelium and induce a leaky BBB. Therefore, we hypothesize that pharmacological inhibition of WNT/beta-catenin signaling in brain endothelial cells will decrease BBB integrity, enabling enhanced paracellular drug delivery to infiltrative GSCs. METHODS We recapitulated the WNT-medulloblastoma phenotype in GBM by activating WNT/beta-catenin signaling in primary human GSCs, inducing secretion of downstream WNT antagonists. Conditioned-media (CM) from GSCs was then applied to human brain microvascular endothelial cells (HBMEC) to indirectly inhibit WNT signaling. Additionally, we directly inhibited WNT/beta-catenin signaling in HBMECs with the small molecule inhibitor ICG-001. Endothelial cell-cell interaction was measured by electrical impedance using the ACEA xCELLigence system. Fenestration and junctional expression were evaluated by immunoblotting and immunofluorescence. RESULTS ICG-001 or WNT-GSC-CM, but not control GSC-CM, upregulated fenestration related protein, PLVAP, and downregulated junctional proteins claudin-5, ZO-1, and VE-Cadherin in HBMECs. Endothelial cell-cell interaction was transiently decreased by ICG-001 or WNT-GSC-CM. Pre-clinical studies are underway to evaluate the functional impact of WNT/beta-catenin inhibition on BBB integrity and permeability in rodent glioma models. Altogether, these results support targeting WNT/beta-catenin signaling in brain endothelial cells to enhance drug delivery to CNS tumors. CONCLUSION Modulation of intratumoral Wnt/beta-catenin signaling, particularly in highly resistant GSCs, may enhance chemotherapy drug delivery, potentially expanding the drug portfolio and improving the prognosis of GBM.

scholarly journals Blood-brain barrier alterations in human brain tumors revealed by genome-wide transcriptomic profiling

2021 ◽  
Author(s):  
Johanna Schaffenrath ◽  
Tania Wyss ◽  
Liqun He ◽  
Elisabeth Jane Rushing ◽  
Mauro Delorenzi ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Endothelial Cells ◽  
Brain Tumor ◽  
Brain Tumors ◽  
Human Brain ◽  
Blood Brain Barrier ◽  
Tumor Stroma ◽  
Brain Barrier ◽  
Human Brain Tumors ◽  
Blood Brain

Abstract Background Brain tumors, whether primary or secondary, have limited therapeutic options despite advances in understanding driver gene mutations and heterogeneity within tumor cells. The cellular and molecular composition of brain tumor stroma, an important modifier of tumor growth, has been less investigated to date. Only few studies have focused on the vasculature of human brain tumors despite the fact that the blood-brain barrier (BBB) represents the major obstacle for efficient drug delivery. Methods In this study, we employed RNA sequencing to characterize transcriptional alterations of endothelial cells isolated from primary and secondary human brain tumors. We used an immunoprecipitation approach to enrich for endothelial cells from normal brain, glioblastoma (GBM) and lung cancer brain metastasis (BM). Results Analysis of the endothelial transcriptome showed deregulation of genes implicated in cell proliferation, angiogenesis and deposition of extracellular matrix (ECM) in the vasculature of GBM and BM. Deregulation of genes defining the BBB dysfunction module were found in both tumor types. We identified deregulated expression of genes in vessel-associated fibroblasts in GBM. Conclusion We characterize alterations in BBB genes in GBM and BM vasculature and identify proteins that might be exploited for developing drug delivery platforms. In addition, our analysis on vessel-associated fibroblasts in GBM shows that the cellular composition of brain tumor stroma merits further investigation.

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